Flexible Battery Interconnect Layout for Cell Swelling Relief

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Solution Overview

Problem

Existing battery module designs face challenges in accommodating the swelling of battery cells, which can lead to mechanical instability and increased production costs due to the need for complex stress relief structures and excessive material usage.

Innovation Solution

A flexible interconnect with a planar stress relief section and non-linear cutouts is implemented, allowing for relative extension between solid parts while maintaining a compact design, enabling automatic assembly and reducing waste and costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex stress relief structures are used to accommodate battery cell swelling, then mechanical stability is improved, but device complexity and manufacturing costs increase

Engineering Contradiction:
Improvemechanical stabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The interconnect is segmented into multiple layers (first interconnect layer, second interconnect layer) with distinct functions. The first layer provides structural support and electrical connection, while the second layer provides stress relief through non-linear cutouts. This segmentation allows each layer to be optimized for its specific function, improving mechanical stability without requiring a single complex structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces non-linear cutouts (meandering patterns, zigzag patterns, or patterns with protrusions/recesses) in the second interconnect layer, which add dimensional complexity in the planar direction rather than requiring three-dimensional structural complexity. This allows the interconnect to accommodate swelling through in-plane deformation while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If complex stress relief structures are used to accommodate battery cell swelling, then mechanical stability is improved, but manufacturing costs increase due to excessive material usage

Engineering Contradiction:
Improvemechanical stabilityVSAvoidmaterial waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

By dividing the stress relief function into a separate second interconnect layer with non-linear cutouts, the design allows for precise material placement only where needed for stress relief. This prevents excessive material usage throughout the entire interconnect structure, reducing manufacturing costs while maintaining mechanical stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The non-linear cutouts are strategically positioned in the second interconnect layer at locations where stress relief is most needed. This local application of stress relief features ensures mechanical stability is improved where required without adding material throughout the entire structure, thereby reducing overall material waste and manufacturing costs.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If traditional interconnect designs are used, then production is simpler, but precise placement and automatic assembly are difficult

Engineering Contradiction:
Improveproduction simplicityVSAvoidplacement precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The interconnect is designed with pre-formed non-linear cutouts and defined attachment features that are created during manufacturing. These pre-formed features guide the placement and alignment processes, enabling automatic assembly systems to accurately position the interconnect on the battery cell array without requiring complex real-time adjustments.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The non-linear cutouts incorporate curved patterns (meandering, zigzag, or patterns with protrusions and recesses) that provide inherent alignment features. These curved geometries create natural reference points that facilitate precise placement during assembly, enabling automatic assembly while maintaining manufacturing simplicity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP4571929A1Battery module
Publication Date: 2025.06.18 SAMSUNG SDI CO LTD
  • EP4571929A1 patent drawingFigure 1~2
  • EP4571929A1 patent drawingFigure 3
  • EP4571929A1 patent drawingFigure 4~5

AI summary

The present disclosure refers to a battery module (1) including a plurality of battery cells (2); a flexible interconnect (10) for providing electrical information of the plurality of battery cells (2) to a battery management unit, wherein the flexible interconnect (10) has an elongated shape in the longitudinal direction of the battery module (1), which defines the longitudinal direction of the flexible interconnect (10), and is affixed to the plurality of one battery cells (2). The flexible interconnect (10) includes at least one stress relief section (20) extending along the longitudinal direction of the battery module (1), the stress relief section (20) includes at least one cutout (23) extending along the longitudinal direction of the flexible interconnect (10), and a plurality of interconnect traces (24) divided from each other by the at least one non-linear cutout (23), the plurality of interconnect traces (24) include a first peripheric interconnect trace (24) forming a recessed portion (25) and a second peripheric interconnect trace (24), opposite to the first interconnect trace (24), forming a protruding portion (26), and a height (b) of the protruding portion (26) in the stress relief section (20) is not larger than a width (ai) of the flexible interconnect (10) neighbouring the stress relief section (20).